1. Field of the Invention
This invention is directed to the loading of microfilm strips into microfilm jackets and, more particularly, to a method and apparatus for automatic insertion of one or more strips into jacket pockets.
2. The Prior Art
Microfilm jackets are now in wide use in the microfilm industry. These jackets generally comprise a pair of transparent plastic sheets formed with a plurality of film channels or pockets. Parallel bonding ribs define the channels and sandwich the sheets together. The side edges of the top sheet are notched or cut back to designate openings through which film is inserted within the pockets. The jackets may be stored in files and carry the microfilm images for scanning or copying and enlarging by photographic or other processes. The jackets lend themselves particularily effectively to contact printing in the production of reference copies.
For a long time, microfilm strips have been sectioned from rolls and then inserted into the channels of the jacket by automatic machinery. In recent years, a new technique develops microfilm images onto individual 6 inch (or 152.4 mm) strips. The film roll loaders presently in use do not lend themselves to insertion of the individual strips into the jackets; hence, the 6 inch strips have had to be manually passed into jacket pockets.
U.S. Pat. No. 2,937,483 to Engelstein is exemplary of a type of film roll-loader equipment in use today. In that equipment, microfilm web is unrolled from a roll and threaded along a horizontal track beneath a feed roller. Downstream of the track, the jacket is supported on an inclined plate. The channel openings are positioned just off the edge of the track and coplanar with the track. Between the feed roller and the end of the track is a film slicer. In operation, the film is transported by the feed roller into registry with the underlying edge of the jacket just below the channel opening. The web, being flexible, tends to curl downward when unrolled; but, since the jacket is inclined and the film is confined by the track, the web is deflected upwardly into the channel. When the film is driven fully into the channel, the slicer is activated to shear the film.
In these film roll loaders, placement of the feed roller along the track is not critical. Succeeding film is unwound to propel the web segment to be loaded. However, once the trail edge of a 6-inch strip is passed beneath a feed roller, movement of the strip stops, leaving the strip unloaded if a film roll loader were used. An upward curl of the ends of the pre-cut, individual strips often occurs. Film roll-loader machinery is ineffective to pass upturned film edges into channel openings since an edge would tend to register with the jacket above the channel opening.
The present invention is directed to the design of an automatic jacket-loading machine for the insertion of pre-cut, individual microfilm strips into jacket pockets.